1,702 research outputs found

    ‘The future costs of nuclear power using multiple expert elicitations: effects of RD&D and elicitation design

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    Characterization of the anticipated performance of energy technologies to inform policy decisions increasingly relies on expert elicitation. Knowledge about how elicitation design factors impact the probabilistic estimates emerging from these studies is, however, scarce. We focus on nuclear power, a large-scale low-carbon power option, for which future cost estimates are important for the design of energy policies and climate change mitigation efforts. We use data from three elicitations in the USA and in Europe and assess the role of government research, development, and demonstration (RD&D) investments on expected nuclear costs in 2030. We show that controlling for expert, technology, and design characteristics increases experts' implied public RD&D elasticity of expected costs by 25%. Public sector and industry experts' cost expectations are 14% and 32% higher, respectively than academics. US experts are more optimistic than their EU counterparts, with median expected costs 22% lower. On average, a doubling of public RD&D is expected to result in an 8% cost reduction, but the uncertainty is large. The difference between the 90th and 10th percentile estimates is on average 58% of the experts' median estimates. Public RD&D investments do not affect uncertainty ranges, but US experts are less confident about costs than Europeans

    The effects of expert selection, elicitation design and R&D assumptions on experts' estimates of the future costs of photovoltaics

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    Expert elicitations of future energy technology costs can improve energy policy design by explicitly characterizing uncertainty. However, the recent proliferation of expert elicitation studies raises questions about the reliability and comparability of the results. In this paper, we standardize disparate expert elicitation data from five EU and US studies, involving 65 experts, of the future costs of photovoltaics (PV) and evaluate the impact of expert and study characteristics on the elicited metrics. The results for PV suggest that in-person elicitations are associated with more optimistic 2030 PV cost estimates and in some models with a larger range of uncertainty than online elicitations. Unlike in previous results on nuclear power, expert affiliation type and nationality do not affect central estimates. Some specifications suggest that EU experts are more optimistic about breakthroughs, but they are also less confident in that they provide larger ranges of estimates than do US experts. Higher R&D investment is associated with lower future costs. Rather than increasing confidence, high R&D increases uncertainty about future costs, mainly because it improves the base case (low cost) outcomes more than it improves the worst case (high cost) outcomes

    Rates of breastfeeding initiation and duration in the United States: data insights from the 2016–2019 Pregnancy Risk Assessment Monitoring System

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    IntroductionWhile breastfeeding rates in the United States have been increasing, they remain low by international standards with substantial racial, income and education disparities. This study uses recent population-based data to analyze sociodemographic differences in breastfeeding initiation, duration, and exposure to information and education.MethodsWe used the 2016–2019 Pregnancy Risk Assessment Monitoring System (PRAMS) to compare breastfeeding duration among a representative population from 43 states and the District of Columbia. We modeled the likelihood of never initiating breastfeeding by respondent’s age, race and ethnicity, language, marital status, household income, educational attainment, parity and insurance status. We also compared sources of information and education for respondents who never breastfed to those who breastfed up to 6 months.ResultsAmong 142,643 new mother respondents, representing an estimated population of 7,426,725 birthing individuals, 12.6% never breastfed, 60.4% reported breastfeeding at 3 months and 54.7% at 6 months. While 75.8% of college graduates reported breastfeeding at 3 months, this was only 37.8% of respondents with high school or less. Among those with the lowest six-month rates were non-Hispanic Black participants (36.3%) and those age < 20 (25.5%). Respondents with Medicaid coverage for their delivery were 25% more likely to have never breastfed than the privately insured. Respondents reporting household income <20,000were5720,000 were 57% more likely to have never breastfed as compared to those with household income>85,000. While 64.1% of those breastfeeding at 6 months reported receiving information from “my” doctor’, this was only 13.0% of those who never breastfeed.DiscussionImproved breastfeeding rates could have significant effects on reducing health disparities in the United States. Clinical and public health policy initiatives need to include culturally sensitive breastfeeding education before and after childbirth, with psychological and direct support from obstetrics and primary care providers. Health plans should support home and community-based in-person and telelactation consulting services. Public policies such as paid family and medical leave and workplace accommodations will also be critical. Given the huge implications of breastfeeding rates on the development of infant immune defenses and a healthy microbiome, improving breastfeeding rates should be a much more important public health priority in the United States

    Pollen metabarcoding reveals broad and species-specific resource use by urban bees

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    Bee populations are currently undergoing severe global declines driven by the interactive effects of a number of factors. Ongoing urbanisation has the potential to exacerbate bee declines, unless steps are taken to ensure appropriate floral resources are available. Sown wildflower strips are one way in which floral resources can be provided to urban bees. However, the use of these strips by pollinators in urban environments remains little studied. Here, we employ pollen metabarcoding of the rbcL gene to compare the foraging patterns of different bee species observed using urban sown wildflower strips in July 2016, with a goal of identifying which plant species are most important for bees. We also demonstrate the use of a non-destructive method of pollen collection. Bees were found to forage on a wide variety of plant genera and families, including a diverse range of plants from outside the wildflower plots, suggesting that foragers visiting sown wildflower strips also utilize other urban habitats. Particular plants within the wildflower strips dominated metabarcoding data, particularly Papaver rhoeas and Phacelia tanacetifolia. Overall, we demonstrate that pollinators observed in sown wildflower strips use certain sown foodplants as part of a larger urban matrix

    Effects of Schizochytrium microalgae and sunflower oil as sources of unsaturated fatty acids for the sustainable mitigation of ruminal biogases methane and carbon dioxide

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    Biogases produced during ruminant production needs to be reduced. The Food and Agriculture Organization (FAO) estimated CH4 production from livestock to contribute about 18% of all greenhouse gas emissions, while carbon dioxide (CO2) accounted for about 9% of the emission (FAO, 2006). Besides, these gases including CH4, CO2, and H2 are produced during ruminal fermentation and cause losses amounting to 2e12% of dietary energy in ruminants (Johnson and Johnson, 1995). Furthermore, these emissions have been implicated in causing climate change. Yeast, organic acids salt, exogenous enzymes, and essential oils have been used as new strategies to mitigate the production of ruminal methane from ruminants (Elghandour et al., 2016, 2017; Hernandez et al., 2017).Mitigation of methane (CH4) and carbon dioxide (CO2) emissions as well as ruminal fermentation parameters of a total mixed ration in the presence of Schizochytrium microalgae (SA) and sunflower oil (SO) or their mixture (SASO) as unsaturated fatty acid sources was investigated. Rumen liquor from two rumen cannulated Holstein steers and two rumen cannulated Creole goats was used as inoculum. Interactions between inoculum source additive type, and inoculum source additive type dose were observed for gas, CH4 and CO2 production and fermentation parameters. Additives affected the fermentation parameters in a dose-dependent manner. With goats’ inoculum, the inclusion of SO (1, 2, 4, 5%), SA (2, 3, 5%) and SASO (1, 3%) increased gas production (GP) and decreased the rate of GP, while with the steer inoculum, SO at 1 and 4% increased GP and the rate of GP. All levels of SA and SASO decreased the asymptotic GP and increased the rate of GP. The goat inoculum decreased CH4 at different doses of SO, SA and SASO whereas the steer inoculum decreased CH4 production. At all doses, additives decreased fermentation pH, protozoal counts, and increased ammonia-N, DM degradability and total bacterial counts. Sunflower oil (i.e., SO) at 1e3%, SA at 1e2%, and SASO at 1e2% were the most efficacious in the nutrition of goats, compared with SO at 1 to 2 in steers. The results suggest that Schizochytrium microalgae and sunflower oil could be a valuable means of sustainably mitigating CH4 and CO2 emissions for improved environmental conditions

    The Retroviral Restriction Ability of SAMHD1, but Not Its Deoxynucleotide Triphosphohydrolase Activity, Is Regulated by Phosphorylation

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    SummarySAMHD1 is a cellular enzyme that depletes intracellular deoxynucleoside triphosphates (dNTPs) and inhibits the ability of retroviruses, notably HIV-1, to infect myeloid cells. Although SAMHD1 is expressed in both cycling and noncycling cells, the antiviral activity of SAMHD1 is limited to noncycling cells. We determined that SAMHD1 is phosphorylated on residue T592 in cycling cells but that this phosphorylation is lost when cells are in a noncycling state. Reverse genetic experiments revealed that SAMHD1 phosphorylated on residue T592 is unable to block retroviral infection, but this modification does not affect the ability of SAMHD1 to decrease cellular dNTP levels. SAMHD1 contains a target motif for cyclin-dependent kinase 1 (cdk1) (592TPQK595), and cdk1 activity is required for SAMHD1 phosphorylation. Collectively, these findings indicate that phosphorylation modulates the ability of SAMHD1 to block retroviral infection without affecting its ability to decrease cellular dNTP levels

    Fishing, pollution, climate change, and the long-term decline of coral reefs off Havana, Cuba

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    Understanding temporal and spatial variation of coral reef communities allows us to analyze the relative effects of local stressors, such as fishing and eutrophication, and global stressors, such as ocean warming. To test for spatial and temporal changes in coral reef communities, we combined recent benthic and fish surveys from 2016 with long-term data, dating back to the late 1990s, from four zones located at different distances from Central Havana, Cuba’s largest population center. These changes may indicate the shifting importance of local vs global stressors affecting reef communities. Regardless of the distance from Havana, we found that coral cover was uniformly low (approximately 10%), whereas macroalgal abundance was often high (approximately 65%). Similarly, fish biomass was low across zones, particularly for herbivorous fishes (approximately 12 g m−2) that are critical ecological drivers of reef structure and coral resilience. Analyses of longer-term trends revealed that coral cover near Havana has been below about 10% since at least 1995, potentially because of local stressors. In contrast, reefs farther from Havana maintained relatively high coral cover (approximately 30%) until the early 2000s, but declined more recently to approximately 15%, putting them near the Caribbean-wide average. These distinct spatial and temporal trajectories of reef communities may be the result of the expansion of local stressors away from Havana as the human population increased, or as fishers ventured farther away to exploit new resources. Alternatively, the more recent decline of reefs farther from population centers may have resulted from increasingly frequent global stressors, such as bleaching events and hurricanes

    Polyurethanes from modified castor oil and chitosan. Synthesis, characterization, in vitro degradation, and cytotoxicity

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    [EN] Polyurethanes (PUs) from castor oil (CO), modified CO (MCO) by transesterification reaction, isophorone diisocyanate (IPDI) in an NCO/OH ratio equal to 1, and chitosan (CS) were synthesized to assess their potential as biomaterials. PUs were characterized by Fourier transform infrared spectroscopy, hydroxyl value (ASTM D1957), thermogravimetric analysis, Shore A hardness (ASTM D2240), and scanning electronic microscopy (SEM). Also, contact angle, water retention and in vitro degradation in PBS, and cell viability on fibroblast were performed. The hydroxyl value confirms CO modification, and IR analysis confirms urethane bond formation. The thermal assay does not show new degradation stages and polyol with a high functionality had better hardness performance due to the increase in cross-linking. The micrograph shows micro-phase separation of both polymers. The contact angle shows the hydrophobic surface with an angle over 65°, and the CS and polyol type do not affect swelling and in vitro degradation due to phase separation between both polymers. The cell viability was over 70% in all cases, and solid polymers and degradation products involve non-cytotoxic effects on the samples. The results suggest a potential for these formulations in the biomedical field.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by Universidad de La Sabana under Grant number ING-160-2015. Also, Jose A. Gomez-Tejedor and Ana Valles-Lluch acknowledge the support of the Spanish Ministry of Economy and Competitiveness (MINECO) through the project DPI2015-65401-C3-2-R (including the FEDER financial support).Arévalo-Alquichire, S.; Ramírez, C.; Andrade, L.; Uscategui, Y.; Diaz, LE.; Gómez-Tejedor, JA.; Vallés Lluch, A.... (2018). Polyurethanes from modified castor oil and chitosan. Synthesis, characterization, in vitro degradation, and cytotoxicity. Journal of Elastomers and Plastics. 50(5):419-434. https://doi.org/10.1177/0095244317729578S41943450
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